What’s everyone’s experience with ebike battery degradation over time?

[48v17ah]

I’ve had my e-bike for about two years now and I’m noticing the range isn’t what it used to be. I used to get close to 50 miles per charge, but now I’m lucky to hit 38-40. I charge it regularly but don’t leave it plugged in overnight. Is this just normal battery aging, or could I be doing something wrong?

[galaxymorph]

What is your milage odometer after 2 years?   After I hit 3000 miles I noticed some minor degradation but I was still thinking maybe it is other factors like terrain, weather, riding style.   Now around 5000 miles I think it is around 80% of original capacity.